Tag: physics
Questions Related to physics
Tyndall effect is shown by:
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particles in colloidal solution.
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particles in a very fine suspension
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large particles like stones.
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both A and B
The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. It is observed in aerosol, iris, milk, etc.
Which of the following phenomenon is involved in Tyndall effect?
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Reflection of light.
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Refraction of light.
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Scattering of light.
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Magnification of light.
The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. The amount of scattering is inversely proportional to the fourth power of wavelength and hence the colour of the colloidal solution is the same as the least coloured wavelength.
Which of the following quantities changes during the process of scattering?
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Speed.
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Wavelength.
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Direction of propagation.
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None of the above.
After scattering, light is spread in all directions and hence the direction of propagation changes. Wavelength, speed and frequency of the light remains unchanged during the process. Also, the intensity of the light ray in a direction changes.
Which of the following occurs in scattering?
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Light is reflected back in the original direction.
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Light is split into its spectrum.
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Photons in the light wave are absorbed by the particles.
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Absorption and re-emission of light energy by small particles.
Scattering is the process of absorption and then re-emission of light energy by particles smaller than the wavelength of the incident light ray.
After scattering, the light moves in:
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the same direction as the original light ray.
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opposite to the original direction of the light ray.
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all directions.
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the direction of the shortest path.
In scattering, light wave is absorbed and re-emitted in all directions without a change in the wavelength of the light ray.
Stars twinkle but planets do not twinkle because
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Stars emit their own light but planets receive light from the stars
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Stars do not from a part of solar system
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Stars from a point source of light while planets are considered as a collection of a large number of point sources of light
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During refraction of star light from the atmosphere, star light bends more towards the normal as compared to the planets
Light of the star is bent many times and in random directions as light is bent when it hits a change in density. This random refraction results in the star winking out - twinkling.
As the thickness of the atmosphere increases colour of scattered light is found in ________ order.
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Blue, violet, yellow, red
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Violet, blue, yellow, red
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Red, yellow, blue, violet
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Violet, blue, red, yellow
The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum because of which blue and violet light reaches our eyes from all directions.
The earth's atmosphere is transparent for the visible light.
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True
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False
True. This is the reason we can see things around us in Earth's atmosphere.
The clear sky appears blue because:
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blue light gets absorbed in the atmosphere.
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ultraviolet radiations are absorbed in the atmosphere.
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violet and blue lights get scattered more than lights of all other colours by the atmosphere.
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light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.
The scattering of light depends on the size of the dust particles and the wavelength of the light. The amount of scattering is inversely proportional to the fourth power of wavelength.
Since, violet and blue lights get scattered more than lights of all other colours by the atmosphere the sky appears blue.
What are the colours of the Sun observed most during sunrise/sunset and noon?
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white and red
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reddish and orange
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yellow and reddish
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orange and blue
During sunrise and sunset the sun rays have to pass through a larger distance and also a greater thickness of air since it is low in the sky. At these positions, the sky looks orange-red colour because photons of red and orange light are least scattered through the atmosphere and are able to reach our eyes.